For something like draped fabric I think using the warp/weft directions of the quad mesh is a good way to show the shape of the surface in an etching style.
For that hand image I only had a triangulated mesh, and got the curves by taking intersections with a set of stacked curved surfaces roughly perpendicular to the directions of the fingers.
Building these surfaces was rather manual though, and since then I’ve done this work, which can be a way of getting these sorts of curves in a more automated way: